Promising ferrimagnetic double perovskite oxides towards high spin polarization at high temperature

We predict through our first-principles calculations that four double perovskite oxides of Bi2ABO6 (AB = FeMo, MnMo, MnOs, CrOs) are half-metallic ferrimagnets. Our calculated results shows that the four optimized structures have negative formation energy, from -0.42 to -0.26 eV per formula unit, which implies that they could probably be realized. In the case of Bi2FeMoO6, the half-metallic gap and Curie temperature are predicted to reach to 0.71 eV and 650 K, respectively, which indicates that high spin polarization could be kept at high temperatures far beyond room temperature. It is believed that some of them could be synthesized soon and would prove useful for spintronic applications.Comment: 4 pages, 3 figure

Simultaneous Measurement for Strain and Temperature Using Fiber Bragg Gratings and Multimode Fibers

An all-fiber sensor capable of simultaneous measurement of temperature and strain is newly presented. The sensing head is formed by a fiber Bragg grating combined with a section of multimode fiber that acts as a Mach-Zehnder interferometer for temperature and strain discrimination. The strain and temperature coefficients of multimode fibers vary with the core sizes and materials. This feature can be used to improve the strain and temperature resolution by suitably choosing the multimode fiber. For a 10 pm wavelength resolution, a resolution of 9.21 μ∈ in strain and 0.26°C in temperature can be achieved

Core-Offset Small-Core-Diameter Dispersion Compensation Fiber Interferometer and its Applications in Fiber Sensors

We propose a core-offset small core diameter dispersion compensation fiber (DCF) interferometer and investigate its applications in fiber sensors. If the transverse force is applied to a short section of the DCF, there is almost no crosstalk on the transmission spectrum between the extinction ratio variation induced by the transverse force and the wavelength shift caused by the longitudinal strain or ambient temperature, which can be applied to measure both transverse and longitudinal strain, or both transverse strain and temperature, simultaneously. The proposed sensors have the advantages of low cost, simple and compact structure, and good reproducibility

Temperature- and Phase-Independent Lateral Force Sensor based on a Core-Offset Multi-Mode Fiber Interferometer

A novel lateral force sensor based on a core-offset multi-mode fiber (MMF) interferometer is reported. High extinction ratio can be obtained by misaligning a fused cross section between the single-mode fiber (SMF) and MMF. With the variation of the lateral force applied to a short section of the MMF, the extinction ratio changes while the interference phase remains almost constant. The change of the extinction ratio is independent of temperature variations. The proposed force sensor has the advantages of temperature- and phase-independency, high extinction ratio sensitivity, good repeatability, low cost, and simple structure. Moreover, the core-offset MMF interferometer is expected to have applications in fiber filters and tunable phase-independent attenuators

Research on the Digital Workshop Layout Based on Steel Material Processing Workshop

AbstractAiming at the layout optimization of the steel structure machining workshop in modern ship manufacturing industry, a digital optimum solution is proposed. First optimize the production flow and enterprise resources and build the 3D visual parametric model. Second using optimization algorithm build the optimum layout model. Third apply estimation method on the optimum model. As for the initial layout plan, build the layout optimum model using the Improved Genetic Algorithm, and find out the minimization solution of the optimum. This paper is helpful for the digital manufacture workshop's layout optimization research

Giant negative magnetoresistance induced by the chiral anomaly in individual Cd3As2 nanowires

Cd3As2 is a newly booming Dirac semimetal with linear dispersion along all three momentum directions and can be viewed as 3D analog of graphene. As breaking of either time reversal symmetry or spatial inversion symmetry, the Dirac semimetal is believed to transform into Weyl semimetal with exotic chiral anomaly effect, while the experimental evidence of the chiral anomaly is still missing in Cd3As2. Here we report the magneto-transport properties of individual Cd3As2 nanowires. Large negative magnetoresistance (MR) with magnitude of -63% at 60 K and -11% at 300 K are observed when the magnetic field is parallel with the electric field direction, giving the evidence of the chiral magnetic effect in Cd3As2 nanowires. In addition, the critical magnetic field BC, where there is an extremum of the negative MR, increases with increasing temperature. As the first observation of chiral anomaly induced negative MR in Cd3As2 nanowires, it may offer valuable insights for low dimensional physics in Dirac semimetals.Comment: 4 figure

Trigger efficiencies at BES III

Trigger efficiencies at BES III were determined for both the J/psi and psi' data taking of 2009. Both dedicated runs and physics datasets are used; efficiencies are presented for Bhabha-scattering events, generic hadronic decay events involving charged tracks, dimuon events and psi' -> pi+pi-J/psi, J/psi -> l+l- events (l an electron or muon). The efficiencies are found to lie well above 99% for all relevant physics cases, thus fulfilling the BES III design specifications.Comment: 6 pages, 4 figure